This invention pertains to tape take-up devices and more specifically, to apparatus and methods for forming a tape pack in a substantially aligned formation as a length of tape is wound onto the tape pack.
Various forms of tape are employed for the storage of data. When we say xe2x80x9ctapexe2x80x9d we mean an elongated strip of substantially flexible material. One form of tape is that of magnetic tape. Other types of tape are known, such as punch tape in which a pattern of perforations is made to correspond to specific data characters. Although various forms of tape are known, some portions of the discussion herein will be primarily presented with regard to magnetic tape for illustrative purposes.
However, it is understood that the instant invention is equally applicable to any type of tape that can be wound onto a drum or the like, and it is further understood that the primary use of magnetic tape for illustrative purposes herein is not intended to limit the instant invention to any particular type of tape, including magnetic tape. Furthermore, when we use the word xe2x80x9ctapexe2x80x9d herein without the use of any specific corresponding modifying words, we mean to include within the meaning of the word xe2x80x9ctapexe2x80x9d any type of tape which can be wound onto a reel, drum, or the like.
Prior art magnetic data storage tape often comprises extremely thin plastic tape along with a substance that is supported on the tape and which can be magnetized. The tape is linearly passed by a writing tape head that is configured to impart, or write, a magnetic pattern on the tape. The magnetic pattern imparted on the tape by the tape head corresponds to various data characters which can be employed to store data on the tape. The data can be recorded in either a digital format or an analog format.
The magnetic tape can be passed by a reading tape head that is configured to detect and measure the magnetic pattern on the tape in order to xe2x80x9creadxe2x80x9d the data that is magnetically stored on the tape. In some instances, the writing head and the reading head can be integrally incorporated into one single tape head which is referred to as a read/write head. Often, tape is wound onto a prior art tape take-up device such as a reel, a spool, or the like, to hold the tape in a secure manner during storage and handling of the tape.
Referring to FIG. 1, a perspective view is shown of a typical prior art tape take-up device 10 which is in the form of a reel. The prior art take-up device 10 comprises a substantially cylindrical drum 12. The drum 12 is positioned between, and connected to, a first flange 14 and a second flange 16. The take-up device 10 is configured to be rotated about an axis of rotation 20. A length of tape (not shown) can be wound around the drum 12 between the first and second flanges 14, 16 as the take-up device 10 is rotated. A slot 18, or the like, can be formed on the drum 12 to provide an anchoring point for one end of the tape.
Now referring to FIG. 2, a top view is shown of a typical prior art tape read/write device 50. As is seen, a first take-up device 10A and a second take-up device 10B, which can be configured as reels, are rotatably supported on a base xe2x80x9cBxe2x80x9d of the device 50. The read/write device 50 includes a tape head xe2x80x9cHxe2x80x9d which can be either a write only head, a read only head, or a combination read/write head. The device 50 can also include various tape guides xe2x80x9cGxe2x80x9d and a tape drive device xe2x80x9cDxe2x80x9d which is configured to pull a length of tape xe2x80x9cTxe2x80x9d past the tape head xe2x80x9cH.xe2x80x9d As is evident, the first and second take-up devices 10A and 10B can be employed in conjunction with one another to each hold at least a portion of a length of tape xe2x80x9cTxe2x80x9d when data is being written onto, or read from, the length of tape.
During operation of the prior art read/write device 50, the first reel 10A which initially holds an entire length of tape xe2x80x9cTxe2x80x9d can be placed onto the base xe2x80x9cBxe2x80x9d so as to be rotatable about a first axis of rotation 20A. The tape xe2x80x9cTxe2x80x9d is held on the first reel 10 A in a coil winding, which is sometimes referred to as a xe2x80x9ctape pack.xe2x80x9d A free end (not shown) of the tape xe2x80x9cTxe2x80x9d can be threaded across the guides xe2x80x9cGxe2x80x9d and the tape head xe2x80x9cHxe2x80x9d as well as the tape drive device xe2x80x9cD.xe2x80x9d The tape xe2x80x9cTxe2x80x9d can then be attached or connected to the second reel 10B in preparation for take-up of the tape onto the second reel.
The first and second reels 10A, 10B can then rotate in the directions indicated by the arrows 52A, 52B, respectively, as the tape xe2x80x9cTxe2x80x9d moves across the tape head xe2x80x9cHxe2x80x9d in the direction indicated by the arrow 54. The tape head xe2x80x9cHxe2x80x9d can read from, or write onto, the tape xe2x80x9cTxe2x80x9d as the tape passes, or moves across, the tape head. As the tape xe2x80x9cTxe2x80x9d moves in the direction 54, the tape unwinds from the first reel 10A and winds onto the second reel 10B. The tape xe2x80x9cTxe2x80x9d can be wound back onto the first reel 10A by reversing the directions of rotation 52A, 52B of the first and second reels 10A, 10B which will cause the tape to move across the tape head xe2x80x9cHxe2x80x9d in a direction which is opposite the direction 54.
Alternatively, the tape xe2x80x9cTxe2x80x9d can be rewound back onto the first reel 10A from the second reel 10B without being moved across the tape head xe2x80x9cH.xe2x80x9d This can be accomplished by extending the tape xe2x80x9cTxe2x80x9d directly from the first reel 10A to the second reel 10B, wherein the tape bypasses the tape head xe2x80x9cH,xe2x80x9d guides xe2x80x9cG,xe2x80x9d and drive device xe2x80x9cD.xe2x80x9d This alternative procedure for rewinding the tape xe2x80x9cTxe2x80x9d onto the first reel 10A from the second reel 10A can be used when no reading or writing by the tape head xe2x80x9cHxe2x80x9d is to be performed during the rewinding of the tape xe2x80x9cTxe2x80x9d back onto the first reel 10A. In one variation of the prior art tape read/write device, the tape head xe2x80x9cHxe2x80x9d can be retracted while the tape is rewound in order to reduce abrasion wear of the tape head as a result of the tape moving across the tape head at a relatively high speed.
Moving to FIG. 3, a top view is shown of the prior art take-up device 10 which is depicted in FIG. 1. As is seen in FIG. 3, the cylindrical drum 12 is located between and attached to a first flange 14 and a second flange 16 which is located in substantially juxtaposed relation to the first flange. The take-up device 10 is configured to rotate about the axis of rotation 20. The second flange 16 is shown broken away to reveal a winding of tape xe2x80x9cT,xe2x80x9d known as a tape pack, which is shown supported about the drum 12. An anomaly 30 which is in the form of a bump is also revealed in the winding of tape xe2x80x9cT.xe2x80x9d As is evident, three sectional views, 3Axe2x80x943A, 3Bxe2x80x94B, and 3Cxe2x80x943C, are taken through the prior art take up device 10, each of which will be discussed below.
Now referring to FIG. 3A, a first sectional view 3Axe2x80x943A through the tape take-up device 10 is shown. The axis of rotation 20 of the take-up device 10 is shown for reference. As is also seen, a portion of the drum 12 is shown between the first and second flanges 14, 16 respectively. One purpose of the first and second flanges 14, 16 is to assist in forming a coil of tape xe2x80x9cTxe2x80x9d as the tape is wound around the drum 12. That is, the first and second flanges 14, 16 are supposed to keep the tape xe2x80x9cTxe2x80x9d in a substantially straight and orderly coil as the tape is wrapped or wound around the drum 12.
To accomplish the aforementioned purpose of assisting in forming the tape xe2x80x9cTxe2x80x9d into an orderly coil on the drum 12, spacing is maintained between the first and second flanges 14, 16. The first and second flanges 14, 16 are generally configured so as to be substantially parallel to one another and to be spaced slightly wider than the width of the tape xe2x80x9cT.xe2x80x9d Ideally, this configuration allows the tape xe2x80x9cTxe2x80x9d to pass freely between the first and second flanges 14, 16 while also being guided thereby so as to form a substantially orderly coil about the drum 12.
However, as illustrated in FIG. 3A, the spacing between the first and second flanges 14, 16 can sometimes be too narrow for the tape xe2x80x9cTxe2x80x9d to pass freely there between. In some cases, the spacing between the first and second flanges 14, 16 can be too narrow for the free passage of the tape xe2x80x9cTxe2x80x9d there between. This can be caused by any of a number of reasons, including manufacturing defects, warping, and damage due to impact or excessive force.
In such cases wherein the flange spacing is too narrow, the tape xe2x80x9cTxe2x80x9d can bind on either or both of the first and second flanges 14, 16 as it is coiled about the drum 12. The binding action of the tape xe2x80x9cTxe2x80x9d on the flanges 14, 16, as the tape is coiled about the drum 12 can cause an anomaly 30 (shown in FIG. 3), such as a bump in the coil of tape. Such an anomaly 30 can result in damage to the tape xe2x80x9cTxe2x80x9d as well as problems associated with writing and reading data to and from the tape, respectively.
Moving to FIGS. 3B and 3C, a second sectional view 3Bxe2x80x943B and a third sectional view 3Cxe2x80x943C are shown, respectively, of the tape take-up device 10 which is depicted in FIG. 3. As is seen with reference to FIG. 3, each of the first and second sectional views 3Bxe2x80x943B and 3Cxe2x80x943C are taken through the take-up device 10 in the locations indicated. With reference to FIG. 3B, it is seen that, at the location of the second sectional view 3Bxe2x80x943B, the first and second flanges 14, 16 are substantially parallel to one another. However, although parallel, the first and second flanges 14, 16 are both deformed, or skewed, in a first direction which is indicated by the arrow 31. Such deformation of the first and second flanges 14, 16 can have any of a number of causes including manufacturing defects and exposure to excessive force or excessive heat.
With reference now to FIG. 3C, it is seen that, at the location of the third sectional view 3Cxe2x80x943C, the first and second flanges 14, 16 are substantially parallel to one another. However, both flanges 14,16 are deformed, or skewed, in a second direction which is indicated by the arrow 32. By referring to both FIGS. 3B and 3C, it is evident that the first and second flanges 14, 16 are skewed in substantially opposite directions 31, 32 at each of the locations of the second and third sectional views 3Bxe2x80x943B, 3Cxe2x80x943C, respectively. The skewed nature of the flanges 14, 16 can cause the flanges to have a wobbling effect as the take-up device 10 rotates about the axis of rotation 20. This wobbling effect is sometimes referred to as xe2x80x9crunout.xe2x80x9d
It is also evident from FIGS. 3B and 3C that, because the flanges 14, 16 are skewed, the tape xe2x80x9cTxe2x80x9d will wobble, or oscillate, from side-to-side along with the flanges 14, 16 as the take-up device 10 rotates about the axis of rotation 20. That is, as the take-up device 10 rotates about the axis 20 the tape xe2x80x9cTxe2x80x9d will wobble back and forth between the first direction 31 and the second direction 32 as the tape winds onto, or off of, the take-up device. Such wobbling of the tape xe2x80x9cTxe2x80x9d from side to side as the tape is wound onto, or wound off of, the take-up device 10 can have a deleterious effect on either the tape itself or the read/write process.
For example, such wobbling of the tape xe2x80x9cTxe2x80x9d can cause the edges of the tape to be forced alternately against opposite sides of the tape guides xe2x80x9cGxe2x80x9d (shown in FIG. 2). Such wobbling can be especially problematic in situations wherein the take-up device 10 rotates at a high speed such as hundreds or thousands of revolutions per minute. This can result in excessive wear of the edges of the tape xe2x80x9cTxe2x80x9d and excessive wear of the tape guides xe2x80x9cG.xe2x80x9d The wobbling condition of the tape xe2x80x9cTxe2x80x9d can also cause excessive and rapid lateral movement of the tape relative to the tape head xe2x80x9cHxe2x80x9d (shown in FIG. 2). Such movement of the tape xe2x80x9cTxe2x80x9d relative to the tape head xe2x80x9cHxe2x80x9d can cause malfunctions or disturbances in the read/write process.
In addition to the problems discussed above, deleterious effects can result from tape xe2x80x9cwanderxe2x80x9d which can occur even when the tape reel 10 is accurately manufactured. That is, since the flanges 14, 16 are ideally spaced slightly farther apart than the width of the tape xe2x80x9cT,xe2x80x9d the tape can thus wander back and forth between the flanges due to natural inherent variances in typical prior art mechanical tape-handling equipment. When wander occurs, an edge of the tape xe2x80x9cTxe2x80x9d can come into contact with one of the flanges 14, 16. This can cause the tape xe2x80x9cTxe2x80x9d to bounce off of the flange 14, 16, but typically not before the edge of the tape has been slightly deformed from the contact. This deformation of the tape xe2x80x9cTxe2x80x9d can not only cause problems in the read/write process, but can also cause the formation of bulges and the like, resulting in skewed tape windings similar to that depicted in FIGS. 3 and 3A.
As is evident from the above discussion, problems are associated with the use of prior art tape take-up devices, including those specifically described above for FIGS. 1 through 3C. What is needed then, is a method and apparatus for winding tape onto a drum or the like which achieve the benefits to be derived from similar prior art devices, but which avoid the shortcomings and detriments individually associated therewith.
The invention includes methods and apparatus for forming a tape pack in a substantially aligned manner by rotating the tape pack so that the tape pack periodically passes a stationary location. At least one dynamic alignment member can be positioned at the stationary location. As the tape pack periodically passes the alignment member, at least the outermost windings of the tape pack are urged into aligned formation by the alignment member.
In accordance with a first embodiment of the present invention, an apparatus for forming a tape pack from a length of tape comprises an alignment member which defines a gap through which the tape pack can be passed to facilitate substantially aligned formation thereof upon a drum or the like.
In accordance with a second embodiment of the present invention, an apparatus for forming a tape pack can comprise a pair of alignment members which are each substantially in the form of rollers configured to rotate about axes which are substantially parallel to one another and substantially perpendicular to the axis of rotation of the drum. A gap is defined between the alignment members through which the tape pack can be passed to facilitate substantially aligned formation thereof.
In accordance with a third and a fourth embodiment of the present invention, respective apparatus include a pair of alignment members which are in the form of substantially conical rollers that are rotatable about substantially parallel axes of rotation, or a pair of alignment members which are in the form of substantially cylindrical rollers that are rotatable about substantially perpendicular axes. In accordance with each of the embodiments, a tape pack can be passed between the respective pair of rollers to facilitate substantially aligned formation of the tape pack.
In accordance with a fifth embodiment of the present invention, an apparatus for forming a tape pack can comprise a pair of spaced substantially conical rollers that define a gap there between, and through which gap the tape pack can be passed to facilitate substantially aligned formation thereof.
In accordance with a sixth embodiment of the present invention, an apparatus for forming a tape pack can comprise a pair of substantially dished discs that are configured to rotate with a drum upon which the tape pack is formed and are also configured to rotate about respective axes which are inclined relative to the drum axis. The inclined alignment axes cause the alignment members to tilt toward the tape pack to define a gap there between through which the tape pack can be passed to facilitate substantially aligned formation thereof.
In accordance with a seventh embodiment of the present invention, an apparatus for forming a tape pack can include a pair of alignment members which are each comprised of a plurality of substantially radial alignment extensions that can be resiliently deflected toward the tape pack by movement of the respective alignment members against a stationary guide. The deflected portion of each respective alignment member acts to define a gap there between through which the tape pack can be passed to facilitate substantially aligned formation thereof.
In accordance with an eighth embodiment of the present invention, an apparatus for forming a tape pack can include a pair of alignment members which are each mounted on a drum on either side of the tape pack formed thereon. Each of the alignment members is substantially in the form of a resiliently deformable conical ring that can be resiliently deflected toward the tape pack by movement of each respective alignment member against a stationary guide. The deflection of each of the alignment members defines a gap through which the tape pack can be passed to facilitate substantially aligned formation thereof.
In accordance with a ninth embodiment of the present invention, a method of forming a tape pack is disclosed. The method includes rotating a drum, winding a length of tape about the drum, and passing the tape between a pair of alignment members to facilitate substantially aligned formation of the tape pack.